<?php // $Id$
if ( count( get_included_files() ) == 1 ) die( '---' );
/**
 * CLAROLINE
 *
 * @version 1.8 $Revision$
 *
 * @copyright (c) 2001-2006 Universite catholique de Louvain (UCL)
 *
 * @license http://www.gnu.org/copyleft/gpl.html (GPL) GENERAL PUBLIC LICENSE
 *
 * @author Claro Team <cvs@claroline.net>
 *
 */
define('TEXTFIELD_FILL',     1);
define('LISTBOX_FILL',        2);

class answerFillInBlanks
{
    /**
     * @var $id id of answer, -1 if answer doesn't exist already
     */
    var $id;

    /**
     * @var $id id of question, -1 if answer doesn't exist already
     */
    var $questionId;

    /**
     * @var $answer complete answer text with blanks
     */
    var $answerText;

    /**
     * @var $answerList list of text within blanks
     */
    var $answerList;

    /**
     * @var $gradeList array list scores of each blank
     */
    var $gradeList;

    /**
     * @var $wrongAnswerList array list of incorrect answers to be added in drop down list
     */
    var $wrongAnswerList;

    /**
     * @var $type fill type of form (text field, drop down list box)
     */
    var $type;

    /**
     * @var $step step in edition form
     */
    var $step;

    //----- Others

    /**
     * @var $response response sent by user and stored in object for easiest use
     * use extractResponseFromRequest to set it
     */
    var $response;

    /**
     * @var $errorList is used to store error that comes on form post
     */
    var $errorList;

    /**
     * @var $tblAnswer
     */
    var $tblAnswer;

    /**
     * constructor
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @param $questionId integer question that use this answer
     * @param $course_id to use the class when not in course context
     * @return string
     */
    function answerFillInBlanks($questionId, $course_id = null)
    {
        $this->questionId = (int) $questionId;

        $this->id = -1;

        // directly fill with an example
        $this->answerText = get_lang('&#91;British people&#93; live in &#91;United Kingdom&#93;.');

        $this->answerList = array();
        $this->gradeList = array();
        $this->wrongAnswerList = array();

        $this->type = TEXTFIELD_FILL;

        $this->step = 1;

        $this->response = array();

        $this->errorList = array();

        $tbl_cdb_names = get_module_course_tbl( array( 'qwz_answer_fib' ), $course_id );
        $this->tblAnswer = $tbl_cdb_names['qwz_answer_fib'];
    }

    /**
     * load answers in object
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function load()
    {
        $sql = "SELECT
                    `id`,
                    `answer`,
                    `gradeList`,
                    `wrongAnswerList`,
                    `type`
            FROM `".$this->tblAnswer."`
            WHERE `questionId` = ".(int) $this->questionId;

        $data = claro_sql_query_get_single_row($sql);

        if( !empty($data) )
        {
            $this->id = (int) $data['id'];
            $this->answerText = $data['answer'];
            if( !empty($data['gradeList']) ) $this->gradeList = explode(',' , $data['gradeList'] );
            if( !empty($data['wrongAnswerList']) ) $this->wrongAnswerList = explode( ',' , $data['wrongAnswerList'] );
            $this->type = $data['type'];

            $this->setAnswerList();

            return true;
        }
        else
        {
            return false;
        }
    }

    /**
     * save object in db
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function save()
    {
        $sqlGradeList = implode( ',' , $this->gradeList );
        $sqlWrongAnswerList = implode( ',' , $this->wrongAnswerList );

        if( $this->id == -1 )
        {
            // insert
            $sql = "INSERT INTO `".$this->tblAnswer."`
                    SET `questionId` = ".(int) $this->questionId.",
                        `answer` = '".claro_sql_escape($this->answerText)."',
                        `gradeList` = '".claro_sql_escape($sqlGradeList)."',
                        `wrongAnswerList` = '".claro_sql_escape($sqlWrongAnswerList)."',
                        `type` = ".(int) $this->type;

            // execute the creation query and get id of inserted assignment
            $insertedId = claro_sql_query_insert_id($sql);

            if( $insertedId )
            {
                $this->id = (int) $insertedId;

                return $this->id;
            }
            else
            {
                return false;
            }
        }
        else
        {
            // update
            $sql = "UPDATE `".$this->tblAnswer."`
                    SET `answer` = '".claro_sql_escape($this->answerText)."',
                        `gradeList` = '".claro_sql_escape($sqlGradeList)."',
                        `wrongAnswerList` = '".claro_sql_escape($sqlWrongAnswerList)."',
                        `type` = ".(int) $this->type."
                    WHERE `id` = ".(int) $this->id;

            // execute and return main query
            if( claro_sql_query($sql) )
            {
                return $this->id;
            }
            else
            {
                return false;
            }
        }
    }

    /**
     * delete answers from db
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function delete()
    {
        if( $this->id != -1 )
        {
            // delete question from all exercises
            $sql = "DELETE FROM `".$this->tblAnswer."`
                    WHERE `id` = ".(int) $this->id;

            if( !claro_sql_query($sql) ) return false;

            $this->id = -1;
        }

        return true;
    }

    /**
     * clone the object
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function duplicate($duplicatedQuestionId)
    {
        $duplicated = new answerFillInBlanks($duplicatedQuestionId);

        $duplicated->answerText = $this->answerText;
        $duplicated->answerList = $this->answerList;
        $duplicated->gradeList = $this->gradeList;
        $duplicated->wrongAnswerList = $this->wrongAnswerList;
        $duplicated->type = $this->type;

        $duplicated->save();

        return $duplicated;
    }

    /**
     * check if the object content is valide (use before using save method)
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function validate()
    {
        // answer cannot be empty
        if( $this->answerText == '' )
        {
            $this->errorList[] = get_lang('Please type the text');
            $this->step = 1;
            return false;
        }

        // answer must contain at least one blank
        $regex = '/\[.*\]/';
        if( ! preg_match($regex, $this->answerText) )
        {
            $this->errorList[] = get_lang('Please define at least one blank with brackets %mask', array('%mask'=>'&#91;...&#93;'));
            $this->step = 1;
            return false;
        }

        return true;
    }

    /**
     * handle the form, get data of request and put in the object, handle commands if required
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean true if form can be checked and saved, false
     */
    function handleForm()
    {
        // for multipage form handling
        if( isset($_REQUEST['step']) )         $this->step = (int) abs($_REQUEST['step']);
        else                                $this->step = 1;

        // for answer
        if( isset($_REQUEST['answer']) )    $this->answerText = trim($this->answerEncode($_REQUEST['answer']));
        else                                $this->answerText = '';
        // and update answerList
        $this->setAnswerList();

        if( isset($_REQUEST['type']))        $this->type = $_REQUEST['type'];
        // else keep the value in object (default or loaded)

        if( isset($_REQUEST['wrongAnswerList']) )
        {
            $encoded = $this->wrongAnswerEncode($_REQUEST['wrongAnswerList']);
            // remove empty lines
            $encodedList = explode("\n", $encoded);
            // remove duplicated entries
            $this->wrongAnswerList = array_unique($encodedList);
        }
        else
        {
            $this->wrongAnswerList = '';
        }

        if( isset($_REQUEST['grade']) && is_array($_REQUEST['grade']) )
        {
            // reinit gradeList
            $this->gradeList = array();
            // all values must be positive
            foreach( $_REQUEST['grade'] as $grade )
            {
                $this->gradeList[] = abs(castToFloat($grade));
            }
        }
        // else keep the value in object (default or loaded)

        //-- cmd
        if( isset($_REQUEST['cmdBack']) )
        {
            if( $this->validate() )
            {
                if( $this->step > 1 ) $this->step--;
            }
            return false;
        }

        if( isset($_REQUEST['cmdNext']) )
        {
            if( $this->validate() )
            {
                $this->step++;
            }
            return false;
        }


        // no special command
        return true;
    }

    /**
     * provide the list of error that validate found
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return array list of errors
     */
    function getErrorList()
    {
        return $this->errorList;
    }

    /**
     * display the answers as a form part for display in quizz submission page
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string html code for display of answer
     */
    function getAnswerHtml()
    {
        if( $this->id == -1 )
        {
            $html = "\n" . '<p>' . get_lang('There is no answer for the moment') . '</p>' . "\n\n";
        }
        else
        {
            $answerCount = count($this->answerList);

            // build replacement
            $replacementList = array();

            if( $this->type == LISTBOX_FILL )
            {
                // build the list shown in list box
                // prepare option list using good and wrong answers
                $allAnswerList = array_merge($this->answerList, $this->wrongAnswerList);

                // alphabetical sort of the list
                natcasesort($allAnswerList);

                $optionList[''] = '';

                foreach( $allAnswerList as $answer )
                {
                    $optionListValue = $this->answerDecode($answer);
                    $optionList[$optionListValue] = $optionListValue;
                }

                for( $i = 0; $i < $answerCount; $i++ )
                {
                    if( isset($this->response[$i]) && array_key_exists($this->response[$i],$optionList) )
                    {
                        $selected = $this->response[$i];
                    }
                    else
                    {
                        $selected = ''; // default is the empty element
                    }

                    $replacementList[] = str_replace('$', '\$', claro_html_form_select('a_'.$this->questionId.'_'.$i, $optionList, $selected));
                }
            }
            else
            {
                for( $i = 0; $i < $answerCount; $i++ )
                {
                    if( isset($this->response[$i]) )     $value = $this->response[$i];
                    else                                $value = '';

                    $replacementList[] = str_replace('$', '\$', ' <input type="text" name="a_'.$this->questionId.'_'.$i.'" size="10" value="'.$value.'" /> ');
                }
            }

            // get all enclosed answers
            $blankList = array();
            foreach( $this->answerList as $answer )
            {
                   // filter slashes as they are modifiers in preg expressions
                $blankList[] = '/\['.preg_quote($this->answerDecode($this->addslashesEncodedBrackets($answer)),'/').'\]/';
            }

            // apply replacement on answer, require limit parameter to replace only the first occurrence in case we
            // have several times the same word in a blank.

            $displayedAnswer = preg_replace( $blankList, $replacementList, claro_parse_user_text($this->answerDecode($this->answerText)), 1 );

            $html =
                '<table width="100%">' . "\n\n"

            .    '<tr>' . "\n"
            .    '<td>' . "\n"

            .    $displayedAnswer  . "\n"

            .    '</td>' . "\n"
            .    '</tr>' . "\n\n"

            .    '</table>' . "\n"
            .    '<p><small>' . get_lang('Fill in blanks') . '</small></p>' . "\n";
        }

        return $html;
    }

    /**
     * display the input hidden field depending on what was submitted in exercise submit form
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string html code for display of hidden sent data
     */
    function getHiddenAnswerHtml()
    {
        $html = "\n" . '<!-- ' . $this->questionId . ' -->' . "\n";

        while( list($key, $response) = each($this->response))
        {
            $html .= '<input type="hidden" name="a_'.$this->questionId.'_'.$key.'" value="'.$response.'" />' . "\n";

        }
        $html .= "\n" . '<!-- ' . $this->questionId . '(end) -->' . "\n";
        return $html;
    }


    /**
     * display the input hidden field depending on what was submitted in exercise submit form
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string html code for display of feedback for this answer
     */
    function getAnswerFeedbackHtml()
    {
        $html =
            '<table width="100%">' . "\n\n"

        .    '<tr height:style="font-weight:italic;font-size:small;">' . "\n"
        .    '<td valign="top">'.get_lang('Answer').'</td>' . "\n"
        .    '</tr>' . "\n\n";

        // get all enclosed answers
        $blankList = array();
        foreach( $this->answerList as $answer )
        {
            // filter slashes as they are modifiers in preg expressions
            $blankList[] = '/\['.preg_quote($this->answerDecode($this->addslashesEncodedBrackets($answer)),'/').'\]/';
        }
        $answerCount = count($blankList);

        // build replacement
        $replacementList = array();

        for( $i = 0; $i < $answerCount; $i++ )
        {
            if( $this->isResponseCorrect($this->response[$i],$this->answerDecode($this->answerList[$i])) )
            {
                // user answer is ok
                $userAnswer = htmlspecialchars($this->answerDecode($this->response[$i]));
            }
            else
            {
                if( empty($this->response[$i]) )
                {
                    // no response for this blank
                    $userAnswer = '&nbsp;&nbsp;&nbsp;&nbsp;';
                }
                else
                {
                    // incorrect response
                    $userAnswer = '<span class="error"><s>'.htmlspecialchars($this->answerDecode($this->response[$i])).'</s></span>';
                }
            }
            
            // 
            $correctAnswer = htmlspecialchars($this->answerDecode($this->answerList[$i]));
            $correctAnswer = htmlspecialchars($correctAnswer);
            
            $replacementList[] = str_replace('$', '\$', '[' . $userAnswer . ' / <span class="correct"><b>'.$correctAnswer.'</b></span>]' . "\n");

        }

        // apply replacement on answer
        // use preg_replace instead of str_replace because if there is several blanks 
        // with same correct value using str_replace will replace each occurence by the 1st one he found
        $displayedAnswer = preg_replace( $blankList, $replacementList, claro_parse_user_text($this->answerDecode($this->answerText)), 1 );

        $html =
            '<table width="100%">' . "\n\n"

        .    '<tr height:style="font-weight:italic;font-size:small;">' . "\n"
        .    '<td valign="top">'.get_lang('Answer').'</td>' . "\n"
        .    '</tr>' . "\n\n"

        .    '<tr>' . "\n"
        .    '<td>' . "\n"

        .    $displayedAnswer  . "\n"

        .    '</td>' . "\n"
        .    '</tr>' . "\n\n"

        .    '</table>' . "\n"
        .    '<p><small>' . get_lang('Fill in blanks') . '</small></p>' . "\n";

        return $html;

    }

    /**
     * display the form to edit answers
     *
     * @param $exId exercise id, required to get stay in the exercise context if required after posting the form
     * @param $askDuplicate display or not the form elements allowing to choose if the question must be duplicated or modified in all exercises
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string html code for display of answer edition form
     */
    function getFormHtml($exId = null, $askDuplicate)
    {
        $html =
            '<form method="post" action="./edit_answers.php?exId='.$exId.'&amp;quId='.$this->questionId.'">' . "\n"
        .    '<input type="hidden" name="cmd" value="exEdit" />' . "\n"
        .    '<input type="hidden" name="step" value="'.$this->step.'" />' . "\n";

        if( $this->step > 1 )
        {
            $html .=
                // populate hidden fields for other steps
                '<input type="hidden" name="answer" value="'.htmlspecialchars($this->answerText).'" />' . "\n"
            .    '<input type="hidden" name="type" value="'.htmlspecialchars($this->type).'" />' . "\n"
            .    '<input type="hidden" name="wrongAnswerList" value="'.htmlspecialchars(implode("\n", $this->wrongAnswerList)).'" />' . "\n\n";

            if( !empty($exId) && $askDuplicate )
            {
                if( isset($_REQUEST['duplicate']) )
                {
                    $html .= '<input type="hidden" name="duplicate" value="'.htmlspecialchars($_REQUEST['duplicate']).'" />' . "\n";
                }
            }

            $html .= '<p>' . get_lang('Please give a weighting to each blank') . '&nbsp;:</p>' . "\n"

            .    '<table border="0" cellpadding="5" width="500">' . "\n";

            $i = 0;
            foreach( $this->answerList as $correctAnswer )
            {
                $value = isset($this->gradeList[$i]) ? $this->gradeList[$i] : '0';

                $html .=
                    '<tr>' . "\n"
                .    '<td width="50%">'.$correctAnswer.'</td>' . "\n"
                .    '<td width="50%">'
                .   '<input type="text" name="grade['.$i.']" size="5" value="'.$value.'" />'
                .   '</td>' . "\n"
                .    '</tr>' . "\n\n"
                ;

                $i++;
            }


            $html .=
                '</table>' . "\n\n"
            .    '<input type="submit" name="cmdBack" value="&lt; ' . get_lang('Back') . '" />&nbsp;&nbsp;'
            .    '<input type="submit" name="cmdOk" value="' . get_lang('Ok') . '" />&nbsp;&nbsp;'
            .     claro_html_button('./edit_question.php?exId='.$exId.'&amp;quId='.$this->questionId, get_lang("Cancel") );
        }
        else
        {
            // populate fields of other steps
            $i = 0;
             foreach( $this->gradeList as $grade )
             {
                 $html .= '<input type="hidden" name="grade['.$i.']" value="'.$grade.'" />' . "\n";
                 $i++;
             }

            if( !empty($exId) && $askDuplicate )
            {
                $html .= '<p>' . html_ask_duplicate() . '</p>' . "\n";
            }

            // answer
            $text = $this->addslashesEncodedBrackets($this->answerText);
            $text = $this->answerDecode($text);

            $html .= '<p>' . get_lang('Please type your text below, use brackets %mask to define one or more blanks', array('%mask'=>'&#91;...&#93;'))   . ' :</p>' . "\n"

            .    claro_html_textarea_editor('answer',$text) . "\n"

            // fill type
            .    '<p>' . get_lang('Fill type') . '&nbsp;:</p>' . "\n"
            .    '<p>' . "\n"
            .    '<input type="radio" name="type" id="textFill" value="'.TEXTFIELD_FILL.'"'
            .    ( $this->type == TEXTFIELD_FILL?'checked="checked"':'')
            .     ' /><label for="textFill">'.get_lang('Fill text field').'</label><br />' . "\n"
            .    '<input type="radio" name="type" id="listboxFill" value="'.LISTBOX_FILL.'"'
            .    ( $this->type == LISTBOX_FILL?'checked="checked"':'')
            .     ' /><label for="listboxFill">'.get_lang('Select in drop down list').'</label><br />' . "\n"
            .    '</p>' . "\n"

            // wrong answers list
            .    '<p>'.get_lang('Add wrong answers for drop down lists <small>(Optionnal. One wrong answer by line.)</small>').'</p>'

            .    '<textarea name="wrongAnswerList" cols="30" rows="5">'.htmlspecialchars($this->answerDecode(implode("\n", $this->wrongAnswerList))).'</textarea>' . "\n"

            .    '<p>' . "\n"
            .    '<input type="submit" name="cmdNext" value="' . get_lang('Next') . ' &gt;" />&nbsp;&nbsp;'
            .     claro_html_button('./edit_question.php?exId='.$exId.'&amp;quId='.$this->questionId, get_lang("Cancel") )
            .    '</p>' . "\n";
        }


        $html .= '</form>';

        return $html;
    }

    /**
     * get all blank in answer text and set the value of answer list
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return array array containing
     */
    function setAnswerList()
    {
        $matches = array();

        $regex = '/\[([^]]*)\]/';

        preg_match_all( $regex, $this->answerText, $matches);

        $this->answerList = array();

        if( is_array($matches[1]) && !empty($matches[1]) )
        {
               $this->answerList = $matches[1];
        }

        return true;
    }

    /**
     * encode the answer : replace forbidden and escaped chars by their html entities
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string encoded answer
     */
    function answerEncode($answer)
    {
        $charsToReplace = array('\[','\]', '<' , '>');
        $replacingChars = array('&#91;','&#93;', '&lt;', '&gt;');

        return str_replace($charsToReplace,$replacingChars,trim($answer));
    }

    /**
     * decode the answer : replace some htmlentities by forbidden and escaped chars for proper display
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string decoded answer
     */
    function answerDecode($answer)
    {
        $charsToReplace = array('&#91;','&#93;', '&lt;', '&gt;', '&#44;');
        $replacingChars = array('[',']', '<' , '>', ',');

        return str_replace($charsToReplace,$replacingChars,trim($answer));
    }

    /**
     * encode the wrong answers list : replace forbidden and escaped chars by their html entities
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string encoded wrong answers list
     */
    function wrongAnswerEncode($wrongAnswer)
    {
        $charsToReplace = array(',' , '<' , '>');
        $replacingChars = array('&#44;' , '&lt;' , '&gt;');

        return str_replace($charsToReplace,$replacingChars,trim($wrongAnswer));
    }

    /**
     * add slahes before encoded [ (&#91;) and ] (&#93;)
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string text with backslashes before encoded brackets
     */
    function addslashesEncodedBrackets($text)
    {
        $charsToReplace = array('&#91;','&#93;');
        $replacingChars = array('\\&#91;','\\&#93;');

        return str_replace($charsToReplace,$replacingChars,trim($text));
    }
    /**
     * read response from request grade it, write grade in object, return grade
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return float question grade
     * @desc return score of checked answer or 0 if nothing was checked
     */
    function gradeResponse()
    {
        $grade = 0;

        $answerCount = count($this->answerList);

        for( $i = 0 ; $i < $answerCount ; $i++ )
        {
            if( $this->isResponseCorrect($this->response[$i],$this->answerDecode($this->answerList[$i])) )
            {
                $grade += $this->gradeList[$i];
            }
        }
        return $grade;
    }

    /**
     * get response of user via $_REQUEST and store it in object
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function extractResponseFromRequest()
    {
        $this->response = array();

        $answerCount = count($this->answerList);

        for( $i = 0; $i < $answerCount ; $i++ )
        {
            if( isset($_REQUEST['a_'.$this->questionId.'_'.$i]) )
            {
                $this->response[$i] = $_REQUEST['a_'.$this->questionId.'_'.$i];
            }
            else
            {
                $this->response[$i] = '';
            }
        }

        return true;
    }

    /**
     * compute grade of question from answer
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return float question grade
     */
    function getGrade()
    {
        $gradeSum = 0;

        foreach( $this->gradeList as $grade )
        {
            $gradeSum += $grade;
        }
           return $gradeSum;
    }

    /**
     * compare two string to check if given response is
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return float question grade
     */
    function isResponseCorrect($response, $correctAnswer)
    {
        if( $this->type == LISTBOX_FILL )
        {
            // case sensitive check when select box are used
            return (bool) ($response == $correctAnswer);
        }
        else
        {
            // case insensitive check when text box are used
            return (bool) (strtolower($response) == strtolower($correctAnswer));
        }
    }

    /**
     * return a array with values needed for tracking
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return array
     */
    function getTrackingValues()
    {
        return $this->response;
    }
}
?>
